Sorry about the ad hoc communication. We are currently in firefighting mode.
Earlier today we started receiving distributed deep search queries from an anonymous Public API client. In order to keep our Registry and Members API up we’ve have temporarily taken down the Public API. As soon as we can isolate Public API traffic we’ll put it back up.
We expect to have the Public API back up in two hours, backed by a machine we hope will handle the additional load. If that isn't the case we'll also deploy code that will limit how far back into search results anonymous clients can crawl.
-Rob